Reflux esophagitis increased the risk of bladder pain syndrome/interstitial cystitis: A 3-year follow-up study

Aims: Reflux esophagitis (RE) is a common disease which has been recognized to be associated with several medical co-morbidities. However, the association between RE and bladder pain syndrome/interstitial cystitis (BPS/IC) is still unknown. The present study aimed to explore the association between these two diseases. Methods: We identified 8,962 female patients who had received a diagnosis of RE as the study cohort. We randomly selected 44,810 subjects to be included as the comparison cohort. Each patient in this study was individually tracked for a 3-year period to identify those who subsequently received a diagnosis of BPS/IC. Cox proportional hazards regressions were carried out to estimate the 3-year risk of BPS/IC following a diagnosis of RE. Results: The incidence of BPS/IC following a diagnosis of RE was 4.3% during the follow-up period for all subjects. The incidence rate of BPS/IC was 2.38 [95% confidence interval (CI): 2.21-2.57] per 100 person-years in patients with RE, and 1.24 (95% CI: 1.18-1.30) per 100 person-years in controls. Cox proportional analysis indicated that the hazard ratio (HR) of BPS/IC for patients with RE was 2.00 (95% CI = 1.82-2.20, P <0.001) that of controls. The adjusted HR of BPS/IC for patients with RE was 1.40 (95% CI = 1.27-1.55, P <0.001) after taking age group, urbanization level, and medical comorbidity into consideration. Conclusion: We found that patients with RE were at a higher risk than with comparison patients for having been subsequently diagnosed with BPS/IC during longitudinal follow-up.